The Cosmos is all that is or ever was or ever will be. Our feeble contemplations of the Cosmos stir us – there is a tingling in the spine, a catch in the voice, a faint sensation, as if falling from a height. We know we are approaching the greatest of mysteries.

The size and age of the Cosmos are beyond ordinary human understanding. Lost somewhere between immensity and eternity is our tiny planetary home. In a cosmic perspective, most human concerns seem insignificant, even petty. And yet our species is young and curious and brave and shows much promise. In the last few millennia we have made the most astonishing and unexpected discoveries about the Cosmos and our place within it, explanations that are exhilarating to consider. They remind us that humans have evolved to wonder, that understanding is a joy, that knowledge is prerequisite to survival. I believe that our future depends on how well we know this Cosmos on which we float like a mote of dust in the morning sky.

These explorations required skepticism and imagination both. Imagination will often carry us to worlds that never were. But without it, we go nowhere. Skepticism enables us to distinguish fancy from fact, to test our speculations. The Cosmos is rich beyond measure – in elegant facts, in exquisite interrelationships, in the subtle machinery of awe.